/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * AddID.java
 * Copyright (C) 2005-2012 University of Waikato, Hamilton, New Zealand
 */

package weka.filters.unsupervised.attribute;

import java.util.Enumeration;
import java.util.Vector;

import weka.core.Attribute;
import weka.core.Capabilities;
import weka.core.Capabilities.Capability;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.SingleIndex;
import weka.core.Utils;
import weka.core.WeightedAttributesHandler;
import weka.core.WeightedInstancesHandler;
import weka.filters.Filter;
import weka.filters.UnsupervisedFilter;

/**
 * <!-- globalinfo-start --> An instance filter that adds an ID attribute to the
 * dataset. The new attribute contains a unique ID for each instance.<br/>
 * Note: The ID is not reset for the second batch of instances when batch mode
 * is used from the command-line, or the FilteredClassifier.
 * <p/>
 * <!-- globalinfo-end -->
 * 
 * <!-- options-start --> Valid options are:
 * <p/>
 * 
 * <pre>
 * -C &lt;index&gt;
 *  Specify where to insert the ID. First and last
 *  are valid indexes.(default first)
 * </pre>
 * 
 * <pre>
 * -N &lt;name&gt;
 *  Name of the new attribute.
 *  (default = 'ID')
 * </pre>
 * 
 * <!-- options-end -->
 * 
 * @author fracpete (fracpete at waikato dot ac dot nz)
 * @version $Revision$
 */
public class AddID extends Filter implements UnsupervisedFilter, OptionHandler, WeightedInstancesHandler, WeightedAttributesHandler {

    /** for serialization */
    static final long serialVersionUID = 4734383199819293390L;

    /** the index of the attribute */
    protected SingleIndex m_Index = new SingleIndex("first");

    /** the name of the attribute */
    protected String m_Name = "ID";

    /** the counter for the ID */
    protected int m_Counter = -1;

    /**
     * Returns a string describing this filter
     * 
     * @return a description of the filter suitable for displaying in the
     *         explorer/experimenter gui
     */
    public String globalInfo() {
        return "An instance filter that adds an ID attribute to the dataset. " + "The new attribute contains a unique ID for each instance.\n\n" + "Note: The ID is not reset for the second batch of instances " + "when batch mode is used from the command-line, or the FilteredClassifier.";
    }

    /**
     * Returns an enumeration describing the available options.
     * 
     * @return an enumeration of all the available options.
     */
    @Override
    public Enumeration<Option> listOptions() {

        Vector<Option> result = new Vector<Option>();

        result.addElement(new Option("\tSpecify where to insert the ID. First and last\n" + "\tare valid indexes.(default first)", "C", 1, "-C <index>"));

        result.addElement(new Option("\tName of the new attribute.\n" + "\t(default = 'ID')", "N", 1, "-N <name>"));

        return result.elements();
    }

    /**
     * Parses a given list of options.
     * <p/>
     * 
     * <!-- options-start --> Valid options are:
     * <p/>
     * 
     * <pre>
     * -C &lt;index&gt;
     *  Specify where to insert the ID. First and last
     *  are valid indexes.(default first)
     * </pre>
     * 
     * <pre>
     * -N &lt;name&gt;
     *  Name of the new attribute.
     *  (default = 'ID')
     * </pre>
     * 
     * <!-- options-end -->
     * 
     * @param options the list of options as an array of strings
     * @throws Exception if an option is not supported
     */
    @Override
    public void setOptions(String[] options) throws Exception {
        String tmpStr;

        tmpStr = Utils.getOption('C', options);
        if (tmpStr.length() != 0) {
            m_Index.setSingleIndex(tmpStr);
        } else {
            m_Index.setSingleIndex("first");
        }

        tmpStr = Utils.getOption('N', options);
        if (tmpStr.length() != 0) {
            m_Name = tmpStr;
        } else {
            m_Name = "ID";
        }

        if (getInputFormat() != null) {
            setInputFormat(getInputFormat());
        }

        Utils.checkForRemainingOptions(options);
    }

    /**
     * Gets the current settings of the filter.
     * 
     * @return an array of strings suitable for passing to setOptions
     */
    @Override
    public String[] getOptions() {

        Vector<String> result = new Vector<String>();

        result.add("-C");
        result.add(getIDIndex());

        result.add("-N");
        result.add(getAttributeName());

        return result.toArray(new String[result.size()]);
    }

    /**
     * Returns the tip text for this property
     * 
     * @return tip text for this property suitable for displaying in the
     *         explorer/experimenter gui
     */
    public String attributeNameTipText() {
        return "Set the new attribute's name.";
    }

    /**
     * Get the name of the attribute to be created
     * 
     * @return the current attribute name
     */
    public String getAttributeName() {
        return m_Name;
    }

    /**
     * Set the new attribute's name
     * 
     * @param value the new name
     */
    public void setAttributeName(String value) {
        m_Name = value;
    }

    /**
     * Returns the tip text for this property
     * 
     * @return tip text for this property suitable for displaying in the
     *         explorer/experimenter gui
     */
    public String IDIndexTipText() {
        return "The position (starting from 1) where the attribute will be inserted " + "(first and last are valid indices).";
    }

    /**
     * Get the index of the attribute used.
     * 
     * @return the index of the attribute
     */
    public String getIDIndex() {
        return m_Index.getSingleIndex();
    }

    /**
     * Sets index of the attribute used.
     * 
     * @param value the index of the attribute
     */
    public void setIDIndex(String value) {
        m_Index.setSingleIndex(value);
    }

    /**
     * Returns the Capabilities of this filter.
     * 
     * @return the capabilities of this object
     * @see Capabilities
     */
    @Override
    public Capabilities getCapabilities() {
        Capabilities result = super.getCapabilities();
        result.disableAll();

        // attributes
        result.enableAllAttributes();
        result.enable(Capability.MISSING_VALUES);

        // class
        result.enableAllClasses();
        result.enable(Capability.MISSING_CLASS_VALUES);
        result.enable(Capability.NO_CLASS);

        return result;
    }

    /**
     * Sets the format of the input instances.
     * 
     * @param instanceInfo an Instances object containing the input instance
     *                     structure (any instances contained in the object are
     *                     ignored - only the structure is required).
     * @return true if the outputFormat may be collected immediately
     * @throws Exception if the format couldn't be set successfully
     */
    @Override
    public boolean setInputFormat(Instances instanceInfo) throws Exception {
        Instances outputFormat;
        Attribute newAttribute;

        super.setInputFormat(instanceInfo);

        m_Counter = -1;
        m_Index.setUpper(instanceInfo.numAttributes());
        outputFormat = new Instances(instanceInfo, 0);
        newAttribute = new Attribute(m_Name);

        if ((m_Index.getIndex() < 0) || (m_Index.getIndex() > getInputFormat().numAttributes())) {
            throw new IllegalArgumentException("Index out of range");
        }

        outputFormat.insertAttributeAt(newAttribute, m_Index.getIndex());
        setOutputFormat(outputFormat);

        return true;
    }

    /**
     * Input an instance for filtering. Filter requires all training instances be
     * read before producing output.
     * 
     * @param instance the input instance
     * @return true if the filtered instance may now be collected with output().
     * @throws IllegalStateException if no input format has been set.
     */
    @Override
    public boolean input(Instance instance) {
        if (getInputFormat() == null) {
            throw new IllegalStateException("No input instance format defined");
        }

        if (m_NewBatch) {
            resetQueue();
            m_NewBatch = false;
        }

        if (!isFirstBatchDone()) {
            bufferInput(instance);
            return false;
        } else {
            convertInstance(instance);
            return true;
        }
    }

    /**
     * Signify that this batch of input to the filter is finished. If the filter
     * requires all instances prior to filtering, output() may now be called to
     * retrieve the filtered instances.
     * 
     * @return true if there are instances pending output
     * @throws IllegalStateException if no input structure has been defined
     */
    @Override
    public boolean batchFinished() {
        if (getInputFormat() == null) {
            throw new IllegalStateException("No input instance format defined");
        }

        if (!isFirstBatchDone()) {
            m_Counter = 0;

            // Convert pending input instances
            for (int i = 0; i < getInputFormat().numInstances(); i++) {
                convertInstance(getInputFormat().instance(i));
            }
        }

        // Free memory
        flushInput();

        m_NewBatch = true;
        m_FirstBatchDone = true;

        return (numPendingOutput() != 0);
    }

    /**
     * Convert a single instance over. The converted instance is added to the end of
     * the output queue.
     * 
     * @param instance the instance to convert
     */
    protected void convertInstance(Instance instance) {
        Instance inst;

        m_Counter++;

        // build instance
        try {
            inst = (Instance) instance.copy();

            // First copy string values from input to output
            copyValues(inst, true, inst.dataset(), outputFormatPeek());

            // Insert the new attribute and reassign to output
            inst.setDataset(null);
            inst.insertAttributeAt(m_Index.getIndex());
            inst.setValue(m_Index.getIndex(), m_Counter);

            push(inst); // No need to copy instance
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Main method for testing this class.
     * 
     * @param args should contain arguments to the filter: use -h for help
     */
    public static void main(String[] args) {
        runFilter(new AddID(), args);
    }
}
